Pulverizer.



F. B. FRANKSK PULVEREZER.

APPLICATION HLED JULY 20. ms.

2 SHtLIS SHEET I.

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APPUCATIUN FELED JULY 2th 1m 1,204,385. Patented NUV. T, 1916.

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it fUNiTi iiisfrAi its time omen FREDERICK B. FRANKS, 0F BATH, NS'YLVANIA.

PULVERIZER llow the "fine particles to pass immediately to"the'screen as they enter the 'pulverizer.

This object I attain by dispensing with the deep sheet metal ring usually employed and I also d spense with the hopper for directing l the material" into the space inclosed by said ff further object of the invention is to reduce the number of separate parts in the yoke'by making the yoke and the means for supporting the blades of an integral structure.

' In the accompanying drawings: Figure 1 is a'sectional elevation on the line 1-1, Fig. 2, illustrating my invention; Fig. 2 is a sectional plan view on the line 22, Fig. 1; Fig. 3 is a; detached perspective view of the yoke showing the blades secured thereto but the pushers remoyed therefrom; and Fig. 4 is a view of my improved yoke having an into alnarrow bracing ring at the top.

efcrringto the drawings, 1 is the grindirig ring mounted in an intermediates ection 2 supported by'a lower section: 3. Located upon the intermediate-section is an 'upper section 4'finwhich the screen. 81is mounted. This'is the general nec'hanism'of a standard pulverizer: j 1 10 is a' vertical sliaft adapted to suitable bearings erm ne-frame; of the machine. This shaft is driven by power and; mounted on the 'shaft',in the presentinstahce, is a belt pulley 12. secured to the shaft is a y'oke 5 having four arm's 6 carrying the ushers 7 and mounted between the ushers are 'tlr crushing balls!) which travel in'jthe grooved face of'the'grinding-ringl. I The yoke, in

Patented Nov. '7, 1916.

1 Application filed July 20, 1916 Serial no. 110,344.

feed trough 16 having a discharge opening which communicates with the interior of the pulverizer, preferably near the center therea of. The material is. fed through this trough by any suitable mechanism and is discharged into the upper section of the pulverizer and as soon as the material'passes into the machine the fine particles are thrown out toward the screen by centrifugal force due to the rotation of the yoke, carrying blades which are hereinafter described. The very fine particles pass through the screen 8-, while the coarser particles work down into thespace between the balls and the grind ing ring 1 and are pulverized by the action of the balls. The fine particles formed by the crushing'action are drawn up and are thrown against the screen by centrifugal force, 'while' the coarser particles are reground to the proper degree of fineness, after which they also pass through the screen.

Heretofore, it has been the practice to secure a deep sheet metal ring to the yoke by rivets and to fasten a number of fan brackets to the ring, also by rivets. A hopper is usually secured to the cap plate and extended into the space within the ring so that thematerial did not escape until it reached the lower portion of the compartment incloscd by the yoke hub. This construction was objectionable, mainly because it impeded the free movement of the fine particles of material to thescreen, thus considerably reducing the capacity of the machine. Furthermore, by making the yoke member of a nuniber'of parts riveted to getlier, the rivets, owing tov the excessive strain to which the yoke was Subjected, would become loose and'the ring, and its parts, would rattle, and would eventually break away from the yoke structure, due to the centrifugal action and to the high speed at which the yoke travels.

By my invention, I dispense entirely with the sheetmetal parts and the rivets for secui ing the parts to the yoke by forming an integral annular flange 21 on the upper portion of the yoke and by forming diagonal,

integral brackets 22, which project from this fiance to which the inclined blades; 23 are secured by means of bolts 24. I also provide integral arms 25 which project from the upper surface of the flange 21. On these arms are brackets 26 to which are secured the vertical blades 27 by bolts 28. In order to reinfor e lhicse lu'arlu-ts. particularly on the larpcr machines, l provide inclined luau-w; 1.". which extend from the arms to the hub port ion oi' the yoke. as clearly shown in Fig. l, The .Ll'lm. rigidly support th \Hllvul blades and the brackets 22 rigid y support the diagonal blades, making an exl-i-eilingly substantial yoke structuri-i which i 1.11mi lik ly to be broken as it is preferably mullc of high grade material and there are no loose purl; other than the boltswliicb retain the liladra' the arms so that the liability of the parts becoming loose and breaking the other elements of the machine is obviated to u great exteiit.

ln machines-of this type the yoke travels '1 NH) ft. per minute and fornierly when any thing bro :0 it was necessary to shut down the mill .1 that the parts could be taken out and repaired. By my invention the fan can ll'l is d sp nsed with and the blade supports. a: well in 0 arms of lhe pusher, are made Lnlesgiui h the \olw l urtliernmre, the fan liilti win hr run-lily removed and re da-owl e i hout dismantling the mill as f l" inerly not the parts can be made much cheaper than when nuinufactured prior to my invention.

In some instances, and particularly in machines of the larger sizes, it may be neces sary to connect the upper portions of the vertical arms 25 and this can be done by the use of a narrow connecting ring 30, as illus trated in Fig. 4, which extends from the upper end of one vertical arm to another and in this case the diagonal strengthening ribs 29 may be dispensed with or used in connection with the ring. The ring is very narrow and preferably of such a shape in cross section that it will not interfere with the free passage of the material to the screen as it will be understood that a certain portion, possibly from 15 to 20% of the material, is of such a fineness as to pass freely to the screen without being ground between the ring and the balls.

The operation of the machine is as follows: The material to be pulverized is fed into the upper portion of the machine by any suitable feed apparatus, such as shown at 16, and flows directly into the chamber inclosed by the screen. The shaft carrying the yoke on which the bladesarc mounted travels at a very high speed and, consequently, any material discharged into the machine will immediately be thrown against the screen by the centrifugal action of the blades. The finer particles of the material, possibly 15 to 20%, are fine enough to pass directly through the screen Without being subjected to the action of the balls, While the coarser particles pass down into the space inclosed by the ring and are subjected to the grinding action. and, as the particles are broken, the finer particles are carried by centrifugal force and whirled against the screen, while the very line particles pass llu-rethrough'. This process is carried on until all of the material is reduced to a pow der. The diagonal blades are for the purpose of lifting the powdered material as it is toruuul and the blades 27 catch the powdered material and direct it against the :u'llwll. lly dispensing with the hopper and the usual wide ring carried by the yoke the output of the mill is greatly increased.

As an instance, the difference between the area of the openings in the old style pulverizer using the wide fan center and the present one 1n which integral arms arc used and in which the fan center is dispensed with is, in a 42" mil], as follows: In a mill using the fan center, the area of opening is about 270 sq. ins, whereas the area of opening in a mill in which the fan center is dis pcnsed with is about 722 sq. ins. Further more, I find by practical experiments that the repairs and labor to operate my improved mill are very much less than the repairs and labor in a mill having the sheet metal fan center and the hopper.

While I have shown one type of pusher, it Will be understood that any suitable pusher may be used without departing from the main features of the invention.

I claim:

1. The combination in a pulverizer, of a frame; a screen; a fixed grinding ring; a driven shaft; a yoke carried by the shaft; grinding balls arranged to be driven by the yoke and to travel in contact with the ring; vertically extendin arms projecting upwardly from the yo e; and fans secured to the said arms, the space between the arms being open for the free passage of the material to the screen.

2. The combination in a pulverizer, of a frame; an annular screen; a fixed grinding ring below the screen; a driven shaft; a yoke carried by the said shaft; balls propolled over the grinding ring by the yoke; upwardly projecting arms; fan blades secured to the arms, the space between the arms being entirely open and the upper portion of the pulverizer inclosed by the screen being free of obstructions with the exception of the arms of the yoke so 'that as'the material enters the pulverizer the f ne particles will be carried immediately to the screen by the centrifugal action of the blades.

3. The combination in a pulverizer, of a frame; an annular screen; a fixed grinding ring; a driven shaft; a yoke carried by the said shaft, said yoke having integral arms; pnshers mounted on the arms; balls propelled over the grindin ring bv the pushers and arranged to trave in contact with the ring; integral brackets projecting from the yoke; and fans secured to the brackets.

4. The combination in a pulvcrizer; of a frame; an annular screen; a grinding ring fan blades are secured, the space between the mounted on the frame; a vertical shaft; a vertical arms being open for the free pas- 15 yoke carried by the shaft having integral sage of the material arms; pushers secured to the arms; balls (1. A yoke for a pulverizer made of a mounted in advance of the pushcrs and ar single casting having integral, radial pusher ranged to travel against the grinding ring, arms projecting from' the lower portion said yoke having a series of integral verti thereof and reinforced vertical arms carry- 20 cal arms provided with brackets; a series of ing brackets to which the fan blades are seintegral inclined brackets; and fan blades cured; and a series of integral diagonal secured to both sets or brackets. brackets to which the diagonal blades are 5. A yoke for a pulverizer made as an secured, said yoke havin a hub arranged integral structure and having integral vertito be secured to a power driven shaft. i cal arms and inclined brackets to which the FREDERICK B. FRANKS. 

